State-of-the-art lithium batteries do not provide sufficient energy to power electric vehicles for an acceptable driving range. This limitation arises because the electrodes, both the anode, typically graphite, and the cathode, typically, layered LiMO2 (M=Mn, Co, Ni), spinel LiMn2O4 and olivine LiFePO4, do not offer sufficient capacity or a high enough electrochemical potential to meet the energy demands. Approaches that are currently being adopted to enhance the energy of lithium-ion batteries include the exploitation of composite cathode structures that offer a significantly higher capacity compared to conventional cathode materials. In particular, lithium-rich and manganese-rich high capacity cathodes, such as xLi2MnO3.(1−x)LiMO2 (M=Mn, Ni, Co) materials (often referred to as ‘layered-layered’ materials, because both the Li2MnO3 and LiMO2 components have layered-type structures) suffer from ‘voltage fade’ on repeated cycling, which reduces the energy output and efficiency of the cell, thereby compromising the management of cell/battery operation.
There is an ongoing need for new electrode materials to ameliorate the problems associated with the voltage fade of ‘layered-layered’ electrode materials. The electrodes, electrochemical cells, and batteries of this invention address this need.